Treaties are a serious legal undertaking both in international and domestic law. Internationally, once in force, treaties are binding on the parties and become part of international law. Domestically, treaties to which the United States is a party are equivalent in status to Federal legislation, forming part of what the Constitution calls "the supreme Law of the Land."

However, the word treaty does not have the same meaning in the United States and in international law. Under international law, a "treaty" is any legally binding agreement between nations. In the United States, the word treaty is reserved for an agreement that is made "by and with the Advice and Consent of the Senate" (Article II, Section 2, Clause 2 of the Constitution). International agreements not submitted to the Senate are known as "executive agreements" in the United States, but they are considered treaties and therefore binding under international law.

For various reasons, Presidents have increasingly concluded executive agreements. Many agreements are previously authorized or specifically approved by legislation, and such "congressional-executive" or statutory agreements have been treated almost interchangeably with treaties in several important court cases. Others, often referred to as "sole executive agreements," are made pursuant to inherent powers claimed by the President under Article II of the Constitution.

Neither the Senate nor the Congress as a whole is involved in concluding sole executive agreements, and their status in domestic law is not fully resolved.

- Abridged from State Dept. Publications and other U.S. government materials